Lithium was discovered when Swedish chemist Johan August Arfvedson was analyzing petalite in 1817. He discovered that the alkali metal in the petalite had properties unlike the other known elements. One year later, William Brande and Humphry Davy were both able to isolate a pure sample of lithium.
Lithium's name is derived from the Greek word "lithos," which means "stone." Robert Bunsen and Augustus Matthiessen were able to produce large quantities of the element in 1855. Lithium is the lightest known metal on the periodic table and is useful in the production of aircraft materials. Lithium carbonate is used to treat manic depression. Lithium is also a component of certain types of batteries.